JPH04309856A - Analyzing meter - Google Patents

Abstract

PURPOSE:To keep the measurement state of a sensor always in an optimum state by detecting the incorrect output of a sensor which is calibrated by the calibration operation and repeating the calibration operation again, in order to achieve the correct calibration. CONSTITUTION:When the difference between the tilt of a new detected quantity line obtained through a new calibration operation by a tilt difference calculation part (analysis part 36) and the tilt of a standard detected quantity line obtained by the preceding calibration operation is calculated, if the difference obtained in the tilt difference calculation part is less than a previously set range, the new detected quantity line obtained in the new calibration operation is judged as a correct detected quantity line in a judging part (analysis part 36).

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an analyzer having a self-diagnosis function.

0003

[Prior Art] Analyzers such as various densitometers and micro-ion meters use sensors to measure the concentration of substances to be measured, process the measurement results, display the measurement contents, and pre-set settings. It issues an alarm when the vehicle is out of the specified range.

0004

[Problems to be Solved by the Invention] However, in the conventional analyzers described above, the sensor is calibrated at preset intervals and timings so that correct values can be obtained through measurement operations. Depending on the nature of the work, there is a problem in that dust, air bubbles, etc. can get into the sensor, causing the sensor's calibration value to deviate significantly, resulting in incorrect measured values being output until the next calibration.

[0005] In particular, in analyzers that automatically calibrate,
There is a problem in that measurement processing is performed based on the output of the sensor calibrated in the calibration operation, and the system malfunctions due to an incorrect value.

In view of the above circumstances, the present invention makes it possible to perform correct calibration by detecting incorrect output of a sensor calibrated by a calibration operation and redoing the calibration operation. The purpose of the present invention is to provide an analyzer that can always maintain optimal measurement conditions.

[Configuration of the invention]

[0008]

[Means for Solving the Problems] In order to achieve the above object, an analyzer according to the present invention, in a first invention, supplies a calibration substance to a sensor and performs calibration based on a value output from the sensor. After creating the line, the analyzer supplies the substance to be measured to the sensor and calculates the amount of the substance to be measured based on the value output from the sensor at this time and the calibration curve. A slope difference calculation unit calculates the difference between the slope of a new calibration curve obtained by performing a calibration operation and the slope of a standard calibration curve obtained by the previous calibration operation, and The present invention is characterized in that it includes a determination section that determines a new calibration curve obtained by a calibration operation to be a correct calibration curve when the obtained difference is less than a preset range.

Further, in the second invention, after supplying a calibration substance to the sensor and creating a calibration curve based on the values output from the sensor, the substance to be measured is supplied to the sensor. At this time, in the analyzer that calculates the amount of the substance to be measured based on the value output from the sensor and the calibration curve, a change in the slope of the new calibration curve obtained by performing a new calibration operation and the previous calibration curve are calculated. There is a slope change difference calculation section that calculates the difference between the slope change of the calibration curve obtained in the calibration operation, and when the difference obtained by this slope change difference calculation section is less than a preset range, the calibration curve The present invention is characterized by comprising a determination section that determines the obtained new calibration curve as a correct calibration curve.

0010

[Operation] In the above configuration, in the first invention,
After the difference between the slope of the new calibration curve obtained in the new calibration operation and the slope of the standard calibration curve obtained in the previous calibration operation is calculated by the slope difference calculation section, the slope difference calculation section When the obtained difference is below a preset range, the determining section determines that a new calibration curve obtained by a new calibration operation is the correct calibration curve.

Further, in the second invention, the slope change difference calculating section calculates the difference between the slope change of the new calibration curve obtained in the new calibration operation and the slope change of the calibration curve obtained in the previous calibration operation. After the difference is calculated, when the difference obtained by this slope change difference calculation section is less than a preset range, the judgment section determines that the new calibration curve obtained by a new calibration operation is the correct calibration curve. be done.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an example of a hydroponic cultivation system using an embodiment of the analyzer according to the present invention.

[0013] The hydroponic system shown in this figure has cultivation room 1.
and an analyzer 2, the analyzer 2 measures the ion concentration of the nutrient solution 3 circulating in the cultivation chamber 1, and displays or prints out the measurement results.

The cultivation room 1 includes a cultivation container 5 whose temperature and humidity are controlled to be optimal for the plants 4 to be cultured, a nutrient solution tank 6 disposed within the cultivation container 5, and a nutrient solution tank 6 which is placed inside the nutrient solution tank 6. PH to measure the pH of the nutrient solution 3 filled with
7 in total, and a conductivity meter 8 for measuring the conductivity of the nutrient solution 3,
A liquid thermometer 9 that measures the temperature of the nutrient solution 3; a nutrient solution intake pipe 11 that takes in the nutrient solution 3 in the nutrient solution tank 6 via a filter 10 disposed in the nutrient solution tank 6; When a command is supplied, the sampling pump 12 pumps out the nutrient solution 3 in the nutrient solution tank 6 through the nutrient solution intake pipe 11 and supplies it to the analysis device 2, and the nutrient solution returned from the analysis device 2 is activated. A return pipe 13 that guides the liquid 3 into the nutrient solution tank 6, and a cultivation bed 1 arranged in the cultivation container 5 and in which the plants 4 to be cultivated are planted.
4, a nutrient solution take-out pipe 15 provided in the nutrient solution tank 6, and a nutrient solution 3 filled in the nutrient solution tank 6 through the nutrient solution take-out pipe 15 when a circulation command is supplied. It is equipped with a circulation pump 16 that takes out the water, supplies it to the cultivation bed 14, and circulates it.

When a circulation command is supplied, the circulation pump 16 operates to take out the nutrient solution 3 filled in the nutrient solution tank 6 and supply it to the cultivation bed 14, and a sampling command is also supplied. When the nutrient solution 3 is filled in the nutrient solution tank 6 is taken out and supplied to the analyzer 2, and when the nutrient solution 3 is supplied through the return pipe 13, the nutrient solution 3 is taken out and supplied to the analyzer 2. Return it to the liquid tank 6.

The analyzer 2 also includes a box 20 formed in a rectangular shape, and a nutrient solution 3 arranged in the casing 20 and supplied through the nutrient solution intake pipe 11, and then a return pipe. a sampling tank 21 which is returned to the nutrient solution tank 6 via the nutrient solution tank 13; a high concentration calibration solution tank 22 disposed within the enclosure 20; and a low concentration calibration solution tank 23 disposed within the enclosure 20; Intake pipes 24 to 26 are individually inserted into the sampling tank 21 to low concentration calibration solution tank 23, and the nutrient solution 3, high concentration calibration solution 27, and low concentration calibration solution 28 are fed through the intake pipes 24 to 26. an analyzer 29 that selectively takes in the ion concentration of the nutrient solution 3; a printer 30 that prints out the analysis results of the analyzer 29; Drainage pipe 31 that takes out the nutrient solution 3, high concentration calibration solution 27, low concentration calibration solution 28, etc. as drainage.
and a drain tank 32 that stores the drain liquid discharged through the drain pipe 31.

Then, the analyzer 29 operates at a preset timing and takes in the high concentration calibration solution 27 and the low concentration calibration solution 28, and the sensor 35 provided in the analyzer 29 takes in the high concentration calibration solution 27 and the low concentration calibration solution 28.
(see Figure 2), and then drain the high-concentration calibration solution 27 and low-concentration calibration solution 28 used for calibration into the drain tank 3.
Discharge to 2. Further, the analyzer 29 operates at a preset timing to operate the sampling pump 12 to take in the nutrient solution 3 filled in the nutrient solution tank 6 and guide it to the sampling tank 21. is taken in and its ion concentration is measured, and then the nutrient solution 3 used for the measurement is discharged into a drain tank 32 as a drain solution.

As shown in FIG. 2, the analyzer 29 includes a sensor 35 for measuring the ion concentration of the nutrient solution 3, the high concentration calibration solution 27, and the low concentration calibration solution 28, and a microprocessor. An analysis unit 36 performs processes such as calibrating signal values, correcting the measured values obtained by the sensor 35, and printing out the measured values obtained by the correction process, and a writing process from the analysis unit 36. When a command is supplied, the inclination data supplied with this write command is stored in a designated location, and when a read command is supplied from the analysis section 36, it is stored in a location designated by this read command. and a slope storage unit 37 that reads out slope data and supplies it to the analysis unit 36.

Then, after taking in the high concentration calibration solution 27 and the low concentration calibration solution 28 at a preset timing and creating a calibration curve based on the output of the sensor 35 installed in the analyzer 29, the calibration is carried out. The used high-concentration calibration liquid 27 and low-concentration calibration liquid 28 are discharged into a drain tank 32 as waste liquid. After this, it is determined whether the calibration curve obtained in the calibration operation is correct. In addition, the sampling pump 12 is operated at a preset timing to take in the nutrient solution 3 filled in the nutrient solution tank 6 and guide it to the sampling tank 21, and then take it in and measure its ion concentration. After that, the nutrient solution 3 used for the measurement is discharged into the drain tank 32 as a drain solution.

Next, the calibration operation of this embodiment will be explained with reference to the flowcharts shown in FIGS. 3 and 4.

First, if the initial setting mode is set, the analysis section 36 of the analyzer 29 first uses the low concentration calibration solution 28 stored in the low concentration calibration solution tank 23 as shown in FIG.
is taken in and guided to the sensor 35, and this sensor 35
After storing the value output from the sensor 35 as the low concentration output value PL1, the low concentration calibration liquid 28 used in the sensor 35 is discharged as a waste liquid to the waste liquid tank 32 (step ST1
).

Next, the analysis section 36 takes in the high concentration calibration liquid 27 stored in the high concentration calibration liquid tank 22, guides it to the sensor 35, and uses the value output from this sensor 35 as the high concentration output value PH1. After storing, the high concentration calibration liquid 28 used in the sensor 35 is discharged as a waste liquid into the waste liquid tank 32 (step ST2).

After that, the analysis section 36 connects the low concentration output value PL1 and the high concentration output value PH1 with a straight line, as shown in FIG. 5, based on the stored low concentration output value and high concentration output value. A calibration curve W1 is created (step ST3) and stored in the slope storage section 37 (step ST4).

When this initial setting is completed and the measurement mode is set, the analysis section 36 operates the sampling pump 12 at a preset timing to collect the nutrient solution filled in the nutrient solution tank 6. 3 is taken in and led to the sampling tank 21, and then taken in and sent to the sensor 3.
5 and measure its ion concentration, calculate the ion concentration of the nutrient solution 3 based on the output value obtained by this measurement operation and the calibration curve W1 stored in the slope storage section 37, This calculation result is supplied to the printer 30 and printed out.

Thereafter, the analysis section 36 discharges the nutrient solution 3 used for the measurement into the drain tank 32 as a drain solution.

Thereafter, at each preset timing, the analysis section 36 repeats the above-described measurement operation of the nutrient solution 3 and prints out the measurement results.

Then, when it is time to calibrate the sensor 35, the analysis section 36 first takes in the low concentration calibration liquid 28 stored in the low concentration calibration liquid tank 23 and supplies it to the sensor 35, as shown in FIG. After the value outputted from the sensor 35 is stored as a new low concentration output value PLn, the low concentration calibration liquid 28 used in the sensor 35 is discharged as a waste liquid to the waste liquid tank 32 (step ST
5).

Next, the analysis section 36 takes in the high concentration calibration liquid 27 stored in the high concentration calibration liquid tank 22, guides it to the sensor 35, and converts the value output from this sensor 35 into a new high concentration output value. After storing it as PHn, the high concentration calibration liquid 27 used in the sensor 35 is discharged into the drain tank 32 as a waste liquid (step ST6).

Thereafter, the analysis section 36 calculates the low concentration output value PLn and the high concentration output value as shown in FIG. 6 based on the stored new low concentration output value PLn and new high concentration output value PHn. PHn with a straight line to create a new calibration curve Wn (step ST7), and compare the slope of this new calibration curve Wn with the slope of the first calibration curve W1 stored in the slope storage section 37. to check whether these differences are within preset tolerance values (step ST8).
).

If these are within the allowable values (step ST8), the analysis section 36 determines that the current calibration was performed correctly, stores the new calibration curve Wn in the slope storage section 37, and performs the next calibration. The ion concentration of the nutrient solution 3 is measured using this calibration curve Wn until the
9).

Further, if the difference between the slope of the new calibration curve Wn and the slope of the first calibration curve W1 stored in the slope storage section 37 is outside the allowable value (step ST8), the analysis section 36 It is determined that there was some kind of error in the calibration operation, and the new calibration curve Wn is discarded. The calibration operation is repeated until the difference with the slope of W1 falls within the allowable value (step ST10).
.

As described above, in this embodiment, whether the difference between the slope of the new calibration curve Wn obtained by the calibration operation and the slope of the first calibration curve Wn obtained by the first calibration operation is within the allowable value? If the new calibration curve Wn obtained by the calibration operation is incorrect due to some mistake, this is detected and the calibration operation is re-performed until the correct calibration curve Wn is obtained. This allows the measurement state of the sensor 35 to be always maintained in an optimal state.

Furthermore, in the above-described embodiment, the present invention has been explained by taking as an example the sensor 35 in which the slopes of the calibration curves W1 and Wn are almost constant; When the sensor changes its slope, it is determined whether the calibration operation is performed correctly using the following procedure.

That is, when the preset calibration timing comes, the analysis section 36 first takes in the low concentration calibration liquid 28 stored in the low concentration calibration liquid tank 23 and uses it as a sensor as shown in FIG. 35, and the value output from this sensor 35 is stored as a new low concentration output value PLn, and then the low concentration calibration liquid used in the sensor 35 is discharged into the drain tank 32 as the drain liquid 28 (step ST11).

Next, the analysis section 36 takes in the high concentration calibration liquid 27 stored in the high concentration calibration liquid tank 22, guides it to the sensor 35, and converts the value output from this sensor 35 into a new high concentration output value. After storing it as PHn, the high concentration calibration liquid 27 used in the sensor 35 is discharged as a waste liquid into the waste liquid tank 32 (step ST12).

Thereafter, the analysis section 36 calculates the low concentration output value PLn and the high concentration output value as shown in FIG. 8 based on the stored new low concentration output value PLn and new high concentration output value PHn. A new calibration curve Wn is created by connecting PHn with a straight line (step ST13), and the calculation shown in the following equation (1) is performed to determine the slope of this calibration curve Wn and the slope is stored in the slope storage section 37. Previous calibration curve W(n-1)
The difference Sn from the slope is calculated (step ST14).

Sn = (PH(n-1)-PL(n-1))
-(PHn-PLn)
...(1) Next, the analysis section 36 performs the calculation shown in the following equation (2), and calculates the slope of the previous calibration curve W(n-1) stored in the slope storage section 37 and the slope storage section 37. The difference from the slope of the stored calibration curve W(n-2) from the previous time is determined (step ST15).

S(n-1) = (PH(n-2)-PL(n
-2))-(PH(n-1)-PL(n-1))
...(2) After this, the analysis unit 36 performs the calculation shown in the following equation (3), and calculates each slope difference Sn obtained by the calculation,
Find the difference d between S(n-1).

d=S(n-1)-Sn

...(3) Next, the analysis section 36 uses this difference d
It is checked whether the difference d is within a preset range (step ST16), and if this difference d is within the range, it is determined that the current calibration was performed correctly and a new calibration curve Wn is set.
is stored in the slope storage unit 37, and the calibration curve W(n-2) from the previous time stored in the slope storage unit 37 is deleted. The ion concentration of the nutrient solution 3 is measured using the calibration curve Wn (steps ST17 and ST18).

Further, if the difference d obtained by the above calculation operation is not within the range (step ST1
6) The analysis unit 36 determines that there was some kind of mistake in the current calibration operation, discards the new calibration curve Wn, and continues until the slope of the new calibration curve obtained by the calibration operation satisfies the above-mentioned conditions. Repeat the calibration operation (step ST1
9).

As described above, in this embodiment, the slope difference Sn between the new calibration curve Wn obtained by the calibration operation and the previous calibration curve W(n-1) and the previous calibration curve W(
The difference d between the slope difference S(n-1) between the calibration curve W(n-1) and the previous calibration curve W(n-2) is obtained by a calibration operation based on whether the difference d is within a preset range. Since it is determined whether the new calibration curve Wn is correct, if the sensor 35 is a sensor whose slope of the calibration curve Wn changes over time, the output of the sensor 35 calibrated by the calibration operation is not correct. When the sensor 35 is not present, it can be detected and the calibration operation can be performed again, thereby making it possible to always keep the measurement state of the sensor 35 in the optimum state.

Furthermore, in each of the above-mentioned embodiments, the present invention has been explained by taking as an example the case where the ion concentration of the nutrient solution 3 is measured by the sensor 35. The present invention may also be applied to measurements of rate, etc., gas analysis processing, other analyzers, etc.

[0043]

[Effects of the Invention] As explained above, according to the present invention, when the output of a sensor calibrated by a calibration operation is incorrect, it is possible to perform correct calibration by detecting this and redoing the calibration operation. , This allows the measurement state of the sensor to be always kept in an optimal state.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a hydroponic cultivation system using an embodiment of an analyzer according to the present invention.

FIG. 2 is a block diagram showing a detailed example of the analyzer shown in FIG. 1;

FIG. 3 is a flowchart showing an example of initial calibration of the analyzer shown in FIG. 1;

FIG. 4 is a flowchart showing each calibration example of the analyzer shown in FIG. 1;

FIG. 5 is a schematic diagram illustrating the operation of the initial calibration example shown in FIG. 3;

6 is a schematic diagram illustrating the operation of each calibration example shown in FIG. 4. FIG.

FIG. 7 is a flowchart showing another embodiment of the analyzer according to the present invention.

8 is a schematic diagram illustrating the operation of each calibration example shown in FIG. 7. FIG.

[Explanation of symbols]

3 Substance to be measured (nutrient solution) 27 Calibration substance (high concentration calibration solution) 28 Calibration substance (low concentration calibration solution) 35 Sensor 36 Slope difference calculation section, slope change difference calculation section, judgment section (analysis section)

Claims (2)

[Claims] 1. After supplying a calibration substance to a sensor and creating a calibration curve based on the value output from the sensor at this time, supplying a substance to be measured to the sensor and outputting from the sensor at this time. In an analyzer that calculates the amount of the substance to be measured based on the calibration curve and the calculated value, the slope of the new calibration curve obtained by performing a new calibration operation and the slope of the new calibration curve obtained by the previous calibration operation are calculated. A slope difference calculation unit calculates the difference between the slope of the reference calibration curve and a new calibration curve obtained by the calibration operation when the difference obtained by this slope difference calculation unit is less than a preset range. An analyzer comprising: a determination section that determines a correct calibration curve. 2. After supplying a calibration substance to the sensor and creating a calibration curve based on the value output from the sensor at this time, supplying the substance to be measured to the sensor and outputting from the sensor at this time. In an analyzer that calculates the amount of the substance to be measured based on the calibration curve and the calculated value, the change in slope of the new calibration curve obtained by performing a new calibration operation and the change in the slope of the new calibration curve obtained by the previous calibration operation are calculated. When the difference obtained by the slope change difference calculation section is less than a preset range, the new calibration obtained by the calibration operation is calculated. An analyzer comprising: a determining section that determines that the curve is a correct calibration curve.